The present invention generally relates to intraocular lens (“IOL”) injectors, and more particularly relates to an injector and method for facilitating injection of an accommodating intraocular lens (hereinafter “AIOL”) having two lenses into an eye.
AIOLs having two optics interconnected by one or more flexible haptics are known, an example of which may be seen in FIG. 1 hereof. While dual optic AIOLs are relatively new, single optic IOLs have been around for decades. Most of the IOL injector art has therefore been developed around the single optic IOL. A common injector design for delivering a single optic IOL into an eye includes a main body having a lumen extending between distal and proximal ends of the main body. A plunger is received at the proximal end of the body and telescopes within the lumen in the manner of a syringe. A tip is provided at the distal end of the injector body and gradually tapers to an opening wherethrough the IOL is expressed from the injector. A single optic IOL is placed inside the lumen and the plunger is advanced to engage and push the IOL through and out the tip. The IOL is made of a material allowing the IOL to compress as it is advanced through the narrowing walls of the tip. As such, the tip opening may be made very small, e.g., about 3 mm or less, which in turn allows for entry of the tip through a smaller incision in the eye. A sub 3 mm incision allows for faster recovery and has become the standard in the cataract surgery field.
AIOLs having two optics generally cannot be used in injectors that have been designed for single optic IOLs described above. IOL injectors are designed to control the interface between the IOL and the plunger. Absent such control, the delicate IOL would likely be damaged during delivery through the injector and rendered useless. Thus, injectors designed for single optic IOLs would probably damage a dual optic AIOL since such an injector would not have precise control over the optic/plunger interface. Injectors specifically designed for dual optic IOLs may be seen in published patent application US 2005/0182419 A1 to George Tsai, published Aug. 18, 2005, and US 2004/0160575 A1 to Ian Ayton et al, published Aug. 19, 2004.
In the Tsai application, an injector is provided having a main body with a plunger and an actuator 104 having a pair of pins 106, 108 which engage the bottom optic. The actuator is manually telescoped along the main body which causes the bottom optic to advance within the lumen of the main body while the upper optic trails along behind the bottom optic. Further advancement of the actuator urge a pair of compacting members 130, 132 forward along with the IOL and actuator. The compacting members also move toward each other to compact, crush and/or fold the IOL. The actuator may then be removed and discarded from the injector main body (see paragraph [0039] thereof) and a plunger is advanced to express the IOL from the injector tip. In another embodiment seen in FIGS. 13-15 thereof, the actuator is in the form of a polymer strip which pulls the bottom optic forward due to the frictional engagement therebetween. In each embodiment, as the first optic is moved forward, the second optic engages an inclined portion of the housing which forces the first optic rearward and downward relative to the advancing second optic. As such, the optics become displaced relative to each other in a flatter, non-coaxial arrangement (see paragraphs [0035] and [0036] thereof).
In the Ayton et al application, the injector includes a pair of opposing engagement faces 212, 242 which are generally flat and constructed from a material to which the outer faces of the viewing elements 122, 124 will self-adhere. The upper engagement surface is advanced forward and downward to pull the optic therealong and displace one optic relative to the other optic. The upper lens compactor having engagement surface 242 is then advanced laterally to “crush” the IOL into a second compacted condition shown in FIG. 18 thereof.
In both the Tsai and Ayton et al publications, one of the optics is engaged and moved in a distal direction toward the tip of the injector to relatively displace the optics. The injectors have many parts to execute the movement necessary to first displace the optics to a non-coaxial position, and then compact the optics for subsequent delivery through the injector tip. The number of parts required for the Tsai and Ayton et al injectors greatly increases the complexity of manufacture and assembly of the injector which adds to the cost thereof. Furthermore, each injector requires at least two separate manipulations to first displace and then compact the optics prior to advancement by the plunger. The more injector manipulations required, the more time needed for the IOL implantation procedure which decreases the efficiency of the procedure.
There thus still exists a need for an dual optic AIOL injector that is relatively easy to manufacture, assemble and use. One or more embodiments of the present invention addresses these and other needs.